There are various kinds of applicators known today which can be utilized to dispense a product or substance into a body cavity or onto the skin of a human or an animal. A tampon applicator is specifically used to insert a catamenial tampon into a woman's vagina to absorb menstrual fluid, blood and other kinds of body fluid.
Tampon applicators are available in a variety of shapes and sizes. Some applicators are constructed of paper, paperboard or cardboard while others are made from plastic or are a laminate of two or more different materials. The applicator can be either a single member wherein the user utilizes her finger to expel the tampon or the applicator can be formed from two or more members which are telescopically assembled. A typical two piece applicator employs a hollow tube for housing the tampon and a second tube or plunger which interacts with the first tube to expel the tampon into a woman's vagina.
In using a one piece applicator, the user will normally hold and position the applicator tube approximate her vagina with her thumb and middle finger. She will then use her index finger to expel the tampon into her vagina. With the two piece applicator, the user will normally hold and position the outer tube of the applicator approximate her vagina with her thumb and middle finger. The inner tube is then pushed into the outer tube by movement of her index finger so as to expel the tampon into her vagina. After the tampon is expelled, the applicator is withdrawn and discarded. It has been found that it is much easier for a woman to control the placement of the outer tube into her vagina when a fingergrip ring is provided on either the inner and/or outer tubes.
An integrally formed fingergrip ring is preferred over a non-integral fingergrip since an integrally formed ring tends to be stronger in shear strength and simplifies manufacturing of the product. The fingergrip ring should be sized and configured to provide control of the applicator to ensure comfortable insertion of a tampon or other substance into a body cavity. Up until now, it has been very difficult to mass produce integrally formed fingergrip rings on tampon applicators, especially paper applicators, having a diameter of less than about 1.25 inches (about 31.75 mm). One reason for this is that paper which has been formed into a small diameter tubular member is very susceptible to being ripped or torn when it is subjected to a curling operation. Accordingly, the apparatuses taught in U.S. Pat. Nos. 1,181,965 and 3,065,677 do not work satisfactory because the frictional forces which are developed between the paper and the curling tool will literally destroy the product.
Now an apparatus has been invented for forming a curl on an end of a tubular member even when the tubular member is formed from paper and has a very small diameter.